Toxicity Effect of Silver Nanoparticles in Brine Shrimp Artemia

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Jan 2, 2014 - nanotoxicology would make an important contribution to the development of a sustainable and safe nanotechnology. Silver nanoparticles have ...
Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 256919, 10 pages http://dx.doi.org/10.1155/2014/256919

Research Article Toxicity Effect of Silver Nanoparticles in Brine Shrimp Artemia Chinnasamy Arulvasu, Samou Michael Jennifer, Durai Prabhu, and Devakumar Chandhirasekar Department of Zoology, Unit of Aquaculture and Animal Tissue Culture, University of Madras, Guindy Campus, Chennai 600 025, India Correspondence should be addressed to Chinnasamy Arulvasu; [email protected] Received 21 August 2013; Accepted 19 October 2013; Published 2 January 2014 Academic Editors: D. Endoh, B. Soto-Blanco, and A. Takagi Copyright © 2014 Chinnasamy Arulvasu et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The present study revealed the toxic effect of silver nanoparticles (AgNPs) in Artemia nauplii and evaluated the mortality rate, hatching percentage, and genotoxic effect in Artemia nauplii/cysts. The AgNPs were commercially purchased and characterized using field emission scanning electron microscope with energy dispersive X-ray spectroscopy. Nanoparticles were spherical in nature and with size range of 30–40 nm. Artemia cysts were collected from salt pan, processed, and hatched in sea water. Artemia nauplii (II instar) were treated using silver nanoparticles of various nanomolar concentrations and LC50 value (10 nM) and mortality rate (24 and 48 hours) was evaluated. Hatching percentage of decapsulated cysts treated with AgNPs was examined. Aggregation of AgNPs in the gut region of nauplii was studied using phase contrast microscope and apoptotic cells in nauplii stained with acridine orange were observed using fluorescence microscope. DNA damage of single cell of nauplii was determined by comet assay. This study showed that as the concentration of AgNPs increased, the mortality rate, aggregation in gut region, apoptotic cells, and DNA damage increased in nauplii, whereas the percentage of hatching in Artemia cysts decreased. Thus this study revealed that the nanomolar concentrations of AgNPs have toxic effect on both Artemia nauplii and cysts.

1. Introduction Nanotechnology is the development and manufacture of materials in the nanometer size range (at least one dimension less than 100 nm) and their application [1]. Nanoparticles (NPs) have become a part of our daily life, in the form of cosmetics [2], drug delivery systems [3], therapeutics [4], and biosensors [5]. However, little is known about their biodistribution and bioactivity. The various interactions of NPs with fluids, cells, and tissues need to be considered, starting at the portal of entry and then via a range of possible pathways towards target organs. A discipline of nanotoxicology would make an important contribution to the development of a sustainable and safe nanotechnology. Silver nanoparticles have gained much popularity on account of their antimicrobial properties [6, 7]. They are extensively used in detergents and wound dressings, which end up in the environment during waste disposal [8]. The release of silver nanoparticle as discrete particles or as composite colloids, and of Ag+ from various types of textiles [9, 10] and

paints used for outdoor facade applications, was observed [11]. However, quantitative data on the release of AgNPs into the aquatic environment and measured environmental concentrations of AgNPs are not currently available. Consequently, the entering of AgNPs into the aquatic environment can only be predicted by models that consider the AgNPs life-cycle from their production till their disposal [12–16]. The most relevant processes that govern the stability and mobility of AgNPs in the aquatic environment are AgNPs agglomeration, aggregation, dispersion, sedimentation, and dissolution. These processes are dependent on the particle physicochemical properties that are in turn influenced by environmental parameters such as pH, temperature, ionic strength, and presence of ligands or natural organic matter [17–19]. Artemia (brine shrimp) is zooplankton that is used to feed larval fishes [20]. Artemia present one common characteristic, that is, their strong adaptability to hypersaline environments, such as permanent salt lakes, coastal lagoons, and man-made salt pans. They play an important role in the

2 energy flow of the food chain in marine environment [21– 24]. Artemia use in toxicology poses a reasonable number of answerable questions, namely, practical considerations of laboratory culture and attainment of cyst, ecological relevance, systematic use, and practical conditions of maintenance and sustainability of laboratory conditions of animal model, thus making achievable a sustainable development of Artemiabased bioassays [25].

2. Materials and Methods 2.1. Chemicals. Silver nanoparticles were purchased as a synthetic source from ALDRICH SIGMA CHEMICALS of molecular weight 107.87 g/mL and 0.02 mg/mL concentration diluted in aqueous buffer and containing sodium citrate as stabilizer. 2.2. Field Emission Scanning Electron Microscope (FESEM) with Energy Dispersive X-Ray Spectroscopy (EDX). The morphology and size of silver nanoparticles were measured by field emission scanning electron microscope (HITACHI SU6600). A minute drop of nanoparticles solution was cast on aluminum foil and subsequently dried in air before transferring it to the microscope. An energy dispersive X-ray detection instrument (EDX) (HORIBA 8121-H) was used to examine the elemental composition of the sample. 2.3. Artemia Cyst Collection, Processing, and Hatching Procedure. Artemia cysts were collected from salt pan of Kelambakkam, Chennai, using net of pore size 150–200 micrometer. Cysts were cleaned and they were filtered and spread on the paper which absorbs water and kept for shadow drying for one night [20]. Decapsulation is the removal of the outer membrane of a cyst called the chorion by dissolution in sodium hypochlorite, without affecting the viability of the embryo. Before hatching procedure the cysts were decapsulated using sodium hypochlorite. Approximately 2 g of the precleaned cysts was incubated in 1 L seawater in a conical plastic contained with graduations at 30 ± 1∘ C. 1,500 lux light intensity was provided continuously by a fluorescent lamp. Aeration was maintained by a small line extending to the bottom of the hatching device from an aquarium air pump. Under these conditions, Artemia cysts were hatched within 24 hours. 2.4. Mortality Rate of Artemia nauplii. The acute toxicity was determined by measuring the adverse effect of various concentrations of silver nanoparticle on brine shrimp Artemia nauplii growth, survival and mortality under intermittent flow-through conditions. The study commenced with